I used to bike only upright commuter style with the largest heaviest elastomer springs seat possible AND a suspension post.

Covid hit, everyone dared using public transportation, so I cycled whenever I would commute.

The route I take to go into town is always windy, often cycling against and into the wind.

Upright means I was a giant air brake.

As a bike reseller, I had a myriad of bikes and saddles at my disposal, and regardless of type of bike, I got the best performance from any bike where the bars were a couple inches below a hard slippery saddle.

This was an abrupt change, but allowed me to cut thru the wind.

My back hurt like hell during cycling and after cycling. I put up with it because it allowed me to do some decent top speeds.

About a month in, I got used to the pain and didn't bother me as much because I was feeling great from my endurance gain.

Sleeping on the floor with just a yoga mat really helped correct my back posture, as my sore back would be gone the next day.

As the weeks went by, my back muscles got stronger, and all pain disappeared.

See, my back muscles were weak and never developed from a lifetime of upright cycling.

I think it boils down to how much back pain there is for the individual. If they constantly end up screaming in pain to need morphine, I would seek professional advice from a gp and not BF.

But if it's just a sore back that appears to subside over a day or two, you're surely not breaking anything, and I would just cycle more.